Diagnostic value of lumbar puncture for the etiological assessment of uveitis: a retrospective cohort of 188 patients

AIM

To assess the relevance of lumbar puncture (LP) for the etiological diagnosis of uveitis and to establish predictive factors associated with its contributory use.

METHODS

We performed a retrospective study of patients with de novo uveitis who were referred to our tertiary hospital for etiological diagnosis of uveitis, between January 2003 and July 2018. We included patients who underwent a LP as part of the etiological assessment of uveitis. LP was considered as contributory if it led to the etiological diagnosis or to correct the initially suspected diagnosis.

RESULTS

One hundred eighty eight of the 1211 patients referred for evaluation (16%) had an LP, among these patients, 93 (49.4%) had abnormal results including 69 (36.7%) patients with hypercellularity, 69 (36.7%) with hyperproteinorachia, and 28 (14.9%) with oligoclonal bands and/or increased IgG index. LP was considered as contributing to the diagnosis in only 31 (16.4%) cases, among which there were 10 (5.3%) contributions to the etiological diagnosis and 21 (11.2%) modifications in the diagnosis classification. Multivariate analysis established that African ethnicity (p < 0.001), bilateral uveitis (p = 0.01), presence of macular edema or retinal serous detachment (p = 0.048), presence of retinal vasculitis (p < 0.001), presence of neurological signs or symptoms (p = 0.01), and contributing cerebral MRI (p < 0.001) were all significantly associated with a contributory LP. LP did not lead to any therapeutic modification.

CONCLUSION

LP direct contribution to the diagnosis was rare and most often detected non-specific abnormalities. LP should be performed only in cases of neurological clinical signs or symptoms, suspicion of multiple sclerosis, Vogt-Koyanagi-Harada, or syphilis.

Relevance of Brain MRI in Patients with Uveitis: Retrospective Cohort on 402 Patients

Aim: To assess the diagnostic value of brain magnetic resonance imaging (bMRI) for the etiological diagnosis of uveitis and to establish predictive factors associated with its advantageous use.Methods: Retrospective study on all patients with de novo uveitis who were referred to our tertiary hospital and who underwent a bMRI between 2003 and 2018.Results: bMRI was contributive in 19 out of 402 cases (5%), among patients with a contributive bMRI, 68% had neurological signs. Univariate analysis established that neurological signs (p < .001), granulomatous uveitis (p = .003), retinal vasculitis (p = .002), and intermediate uveitis (p < .001) were all significantly associated with a contributive bMRI. Multivariate analysis confirms the significant association of neurological signs (p < .001) and intermediate uveitis (p = .01).Conclusion: bMRI appears to be a relevant exam in specific cases; intermediate/posterior uveitis or panuveitis accompanied by neurological signs, retinal vasculitis, or in patients older than 40, to rule out an oculocerebral lymphoma.Abbreviations: ACE: Angiotensin-Converting Enzyme; bMRI: Magnetic Resonance Imaging; CBC: Complete Blood cell Count; BMRI: Brain Magnetic Resonance Imaging; CT: Computerized Tomography; MS: Multiple Sclerosis; NS: Neurological Signs; OCL: Oculocerebral Lymphoma; RIS: Radiologically Isolated Syndrome.

Association of rare missense variants in the second intracellular loop of NaV1.7 sodium channels with familial autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder often accompanied by intellectual disability, language impairment and medical co-morbidities. The heritability of autism is high and multiple genes have been implicated as causal. However, most of these genes have been identified in de novo cases. To further the understanding of familial autism, we performed whole-exome sequencing on five families in which second- and third-degree relatives were affected. By focusing on novel and protein-altering variants, we identified a small set of candidate genes. Among these, a novel private missense C1143F variant in the second intracellular loop of the voltage-gated sodium channel Na_V1.7, encoded by the SCN9A gene, was identified in one family. Through electrophysiological analysis, we show that Na_V1.7^C1143F exhibits partial loss-of-function effects, resulting in slower recovery from inactivation and decreased excitability in cultured cortical neurons. Furthermore, for the same intracellular loop of Na_V1.7, we found an excess of rare variants in a case-control variant-burden study. Functional analysis of one of these variants, M932L/V991L, also demonstrated reduced firing in cortical neurons. However, although this variant is rare in Caucasians, it is frequent in Latino population, suggesting that genetic background can alter its effects on phenotype. Although the involvement of the SCN1A and SCN2A genes encoding Na_V1.1 and Na_V1.2 channels in de novo ASD has previously been demonstrated, our study indicates the involvement of inherited SCN9A variants and partial loss-of-function of Na_V1.7 channels in the etiology of rare familial ASD.

Identification of rare variants from exome sequence in a large pedigree with autism

We carried out analyses with the goal of identifying rare variants in exome sequence data that contribute to disease risk for a complex trait. We analyzed a large, 47-member, multigenerational pedigree with 11 cases of autism spectrum disorder, using genotypes from 3 technologies representing increasing resolution: a multiallelic linkage marker panel, a dense diallelic marker panel, and variants from exome sequencing. Genome-scan marker genotypes were available on most subjects, and exome sequence data was available on 5 subjects. We used genome-scan linkage analysis to identify and prioritize the chromosome 22 region of interest, and to select subjects for exome sequencing. Inheritance vectors (IVs) generated by Markov chain Monte Carlo analysis of multilocus marker data were the foundation of most analyses. Genotype imputation used IVs to determine which sequence variants reside on the haplotype that co-segregates with the autism diagnosis. Together with a rare-allele frequency filter, we identified only one rare variant on the risk haplotype, illustrating the potential of this approach to prioritize variants. The associated gene, MYH9, is biologically unlikely, and we speculate that for this complex trait, the key variants may lie outside the exome.

Preferential Utilization of Cellobiose by Thermomonospora curvata

Thermomonospora curvata was cultivated on mineral salts medium containing glucose and cellobiose under conditions that increasingly favored the uptake of glucose. In each case cellobiose was utilized in preference to glucose and induced beta-glucosidase and endoglucanase activity. [C]glucose metabolism studies indicated that cellobiose was not cleaved by extracellular beta-glucosidase and transported as glucose. No evidence of cellobiose phosphorylase or a cellobiose-specific phosphoenolpyruvate-phosphotransferase system was observed.

Patients with neuroglycopenia after gastric bypass surgery have exaggerated incretin and insulin secretory responses to a mixed meal

CONTEXT AND OBJECTIVE

Hyperinsulinemic hypoglycemia is newly recognized as a rare but important complication after Roux-en-Y gastric bypass (GB). The etiology of the syndrome and metabolic characteristics remain incompletely understood. Recent studies suggest that levels of incretin hormones are increased after GB and may promote excessive beta-cell function and/or growth.

PATIENTS AND METHODS

We performed a cross-sectional analysis of metabolic variables, in both the fasting state and after a liquid mixed-meal challenge, in four subject groups: 1) with clinically significant hypoglycemia [neuroglycopenia (NG)] after GB surgery, 2) with no symptoms of hypoglycemia at similar duration after GB surgery, 3) without GB similar to preoperative body mass index of the surgical cohorts, and 4) without GB similar to current body mass index of the surgical cohorts.

RESULTS

Insulin and C-peptide after the liquid mixed meal were both higher relative to the glucose level achieved in persons after GB with NG compared with asymptomatic individuals. Glucagon, glucagon-like peptide 1, and glucose-dependent insulinotropic peptide levels were higher in both post-GB surgical groups compared with both overweight and morbidly obese persons, and glucagon-like peptide 1 was markedly higher in the group with NG. Insulin resistance, assessed by homeostasis model assessment of insulin resistance, the composite insulin sensitivity index, or adiponectin, was similar in both post-GB groups. Dumping score was also higher in both GB groups but did not discriminate between asymptomatic and symptomatic patients. Notably, the frequency of asymptomatic hypoglycemia after a liquid mixed meal was high in post-GB patients.

CONCLUSION

A robust insulin secretory response was associated with postprandial hypoglycemia in patients after GB presenting with NG. Increased incretin levels may contribute to the increased insulin secretory response.

EEG mu rhythm and imitation impairments in individuals with autism spectrum disorder

Imitation ability has consistently been shown to be impaired in individuals with autism. A dysfunctional execution/observation matching system has been proposed to account for this impairment. The EEG mu rhythm is believed to reflect an underlying execution/observation matching system. This study investigated evidence of differential mu rhythm attenuation during the observation, execution, and imitation of movements and examined its relation to behaviorally assessed imitation abilities. Fourteen high-functioning adults with autism spectrum disorder (ASD) and 15 IQ- and age-matched typical adults participated. On the behavioral imitation task, adults with ASD demonstrated significantly poorer performance compared to typical adults in all domains of imitation ability. On the EEG task, both groups demonstrated significant attenuation of the mu rhythm when executing an action. However, when observing movement, the individuals with ASD showed significantly reduced attenuation of the mu wave. Behaviorally assessed imitation skills were correlated with degree of mu wave attenuation during observation of movement. These findings suggest that there is execution/observation matching system dysfunction in individuals with autism and that this matching system is related to degree of impairment in imitation abilities.

Leishmania and the pathogenesis of HIV infection

Acquired immunodeficiency syndrome (AIDS) and leishmaniasis overlap in several parts of the world, and microorganisms responsible for these human diseases infect and replicate within the macrophage. Therefore, the opportunity that the pathogenesis of the human immunodeficiency virus (HIV) and Leishmania infections could be modulated within dually infected individual is optimized. The most prominent clinical feature of AIDS is the development of debilitating secondary infections induced by several opportunistic microorganisms, including protozoa. Michel Tremblay, Martin Olivier and Richard Bernier here focus on the recently reported information on the putative cofactor role that the intracellular pathogen of the genus Leishmania may play in the pathogenesis of HIV infection.

Assessing immunization coverage in private practice

To achieve national health objectives of eliminating most childhood vaccine-preventable diseases by the year 2010, all health care providers will have to improve the immunization rates of their patients. Currently, immunization rates of children 19 to 35 months of age are less than national objectives, suggesting a need for optimized immunization services. A key strategy for improving age-appropriate immunization coverage by health care providers is the assessment of immunization coverage. Because most (62%), immunization services in the United States are delivered in the private sector, a concerted effort in private practice is critical to improving immunization rates. Assessment of immunization coverage of patients enrolled in private practice serves 1) to measure the overall performance of the practice in providing the standard of care, 2) to identify strategies for improving coverage, and 3) to document the quality of health services delivered (report card). Assessment of immunization coverage has been demonstrated in several practice settings to be highly effective in improving immunization rates. All types of physicians should benefit from assessing immunization coverage of their patients. Simple assessment tools are available at no cost to the public and can be obtained by contacting the Centers for Disease Control and Prevention. These tools include a manual self-assessment or a computerized software package (CASA) to fit the needs of the practice.

An autosomal genomic screen for autism. Collaborative linkage study of autism

Autism is a severe neurodevelopmental disorder defined by social and communication deficits and ritualistic-repetitive behaviors that are detectable in early childhood. The etiology of idiopathic autism is strongly genetic, and oligogenic transmission is likely. The first stage of a two-stage genomic screen for autism was carried out by the Collaborative Linkage Study of Autism on individuals affected with autism from 75 families ascertained through an affected sib-pair. The strongest multipoint results were for regions on chromosomes 13 and 7. The highest maximum multipoint heterogeneity LOD (MMLS/het) score is 3.0 at D13S800 (approximately 55 cM from the telomere) under the recessive model, with an estimated 35% of families linked to this locus. The next highest peak is an MMLS/het score of 2.3 at 19 cM, between D13S217 and D13S1229. Our third highest MMLS/het score of 2.2 is on chromosome 7 and is consistent with the International Molecular Genetic Study of Autism Consortium report of a possible susceptibility locus somewhere within 7q31-33. These regions and others will be followed up in the second stage of our study by typing additional markers in both the original and a second set of identically ascertained autism families, which are currently being collected. By comparing results across a number of studies, we expect to be able to narrow our search for autism susceptibility genes to a small number of genomic regions. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:609-615, 1999.

Antiplatelet and lipid-lowering therapies for the secondary prevention of cardiovascular disease: are we doing enough?

OBJECTIVE

To evaluate whether current recommendations with respect to the treatment of dyslipidemias and the use of antiplatelet agents are being applied in the secondary prevention of cardiovascular disease in primary care settings.

DESIGN

Descriptive study based on data from the FAMUS (FAmily Medicine, Université de Sherbrooke) primary care register.

SETTING AND PARTICIPANTS

Two-hundred and thirty-three physicians participating in the FAMUS project contributed information from nonpregnant patients over 20 years of age consulting for a periodic health examination between 1992 and 1996.

INTERVENTIONS

Data from patients in secondary prevention (those with or having had angina, a previous myocardial infarction, bypass surgery, coronary angioplasty or peripheral vascular disease) were extracted and analyzed.

MAIN RESULTS

Of the 52,505 patients in the register, 4315 (8%) were identified as being in secondary prevention. Overall, 53% were noted as receiving an antiplatelet agent while 4% were taking warfarin therapy. Only 64% (2780) had a complete lipid profile on record while 38% were being treated with a hypolipidemic agent. In the treated group, only 30% had a low density lipoprotein cholesterol level below 3.0 mmol/L compared with 22% in the untreated group.

CONCLUSIONS

A large number of patients identified as being in secondary prevention were not screened for dyslipidemias, and, of those who were, the majority were undertreated according to current recommendations. Antiplatelet agents were more widely prescribed but potentially underused.

Mycobacterium tuberculosis mannose-capped lipoarabinomannan can induce NF-kappaB-dependent activation of human immunodeficiency virus type 1 long terminal repeat in T cells

Tuberculosis has emerged as an epidemic, extended by the large number of individuals infected with human immunodeficiency virus type 1 (HIV-1). The major goal of this study was to determine whether the mycobacterial cell wall component mannose-capped lipoarabinomannan (ManLAM) of Mycobacterium tuberculosis (M. tuberculosis) could activate transcription of HIV-1 in T cells with the use of an in vitro cell culture system. These experiments are of prime importance considering that CD4-expressing T lymphocytes represent the major virus reservoir in the peripheral blood of infected individuals. Using the 1G5 cell line harbouring the luciferase reporter gene under the control of the HIV-1 LTR, it was first found that culture protein filtrates (CFP) from M. tuberculosis or purified ManLAM could activate HIV-1 LTR-dependent gene expression unlike similarly prepared CFP extracts devoid of ManLAM. The implication of protein tyrosine kinase(s), protein kinase A and/or protein kinase C was highlighted by the abrogation of the ManLAM-mediated activation of HIV-1 LTR-driven gene expression using herbimycin A and H7. It was also determined, using electrophoresis mobility shift assays, that M. tuberculosis ManLAM led to the nuclear translocation of the transcription factor NF-kappaB. M. tuberculosis ManLAM resulted in clear induction of the luciferase gene placed under the control of the wild-type, but not the kappaB-mutated, HIV-1 LTR region. Finally, the ManLAM-mediated activation of HIV-1 LTR transcription was found to be independent of the autocrine or paracrine action of endogenous TNF-alpha. The results suggest that M. tuberculosis can upregulate HIV-1 expression in T cells and could thus have the potential to influence the pathogenesis of HIV-1 infection.

Cardiovascular disease. Physician attitudes toward prevention and treatment

OBJECTIVE

Survey of physician attitudes toward practising cardiovascular disease prevention.

DESIGN

Questionnaire administered via telecommunication from 1992 through 1994.

SETTING

The FAMUS (Family Medicine, University of Sherbrooke) project, between 1992 and 1996, used weekly telecommunication to collect data from 200 general practitioners throughout the province of Quebec on cardiovascular disease risk factors and their treatment.

PARTICIPANTS

Of 200 physicians contributing to the FAMUS project, 156 completed questionnaires (response rate 78%).

MAIN OUTCOME MEASURES

Variations in attitudes to prevention policy and risk factor interventions.

RESULTS

Survey results revealed physicians knew important risk factors for cardiovascular disease but differed in attitudes toward efficacy of treatment. Intervention to control cholesterol was thought to be very effective by 21.2% (95% confidence interval [CI] 21.2 +/- 6.4) and without effect by 10.3% (95% CI 10.3 +/- 4.8). Intervention to improve dietary habits was considered ineffective by 48.1% (95% CI 48.1 +/- 7.8). Confidence in managing risk factors varied; most respondents described themselves as only moderately skilled. A few practitioners (30.1%; 95% CI 30.1 +/- 7.2) acknowledged practice guidelines as an important source of information on which to base preventive interventions. Only 14.7% (95% CI 14.7 +/- 5.6) of those surveyed included remuneration as contributing to their implementation of prevention activities in practice.

CONCLUSIONS

Variations in physician attitudes could influence risk factor intervention. Interventions to change lifestyle are associated with uncertainty about patient compliance, efficacy of treatment, and ability to effect lifestyle changes.

The lipophosphoglycan of Leishmania donovani up-regulates HIV-1 transcription in T cells through the nuclear factor-kappaB elements

We have recently demonstrated that the parasite Leishmania donovani and its surface molecule, lipophosphoglycan (LPG), can activate HIV-1 replication in monocytoid cells. Our present interest was to determine whether LPG could also up-regulate HIV-1 transcription in T cells. Using a CD4-positive human lymphoid T cell line (1G5) containing a stably integrated HIV-1 long terminal repeat (LTR)-luciferase construct, we found that LPG is a potent inducer of HIV-1 LTR activity. Treatment of 1G5 cells with signaling antagonists revealed that protein tyrosine kinase- and protein kinase A-dependent pathways were actively participating in the LPG-induced enhancement of HIV-1 LTR-driven activity. Transfection of Jurkat E6.1 cells with plasmids containing wild-type and nuclear factor-kappaB (NF-kappaB)-mutated HIV-1 LTR-luciferase constructs has suggested a role for NF-kappaB binding sites in the LPG-mediated induction of HIV-1 LTR activity. An LPG-induced binding factor specific to the NF-kappaB consensus sequences could be observed using electrophoretic mobility shift assay. Finally, transfection experiments performed with a vector containing HIV-1 kappaB binding sites only showed similar LPG-mediated induction, which was abrogated by sodium salicylate, a known NF-kappaB inhibitor. We thus demonstrate that the LPG-mediated induction of HIV-1 LTR activity in T cells involves several second messengers culminating in activation of HIV-1 LTR-driven transcription via NF-kappaB-binding consensus sequences. In conclusion, these results reinforce the idea that L. donovani is a putative cofactor in HIV-1 pathogenesis.

Activation of HIV-1 long terminal repeat transcription and virus replication via NF-kappaB-dependent and -independent pathways by potent phosphotyrosine phosphatase inhibitors, the peroxovanadium compounds

Replication of human immunodeficiency virus type 1 (HIV-1) is increased by different cytokines and T cell activators, also known to modulate tyrosine phosphorylation levels. A novel class of protein tyrosine phosphatase (PTP) inhibitors, peroxovanadium (pV) compounds, were tested for a putative effect on HIV-1 long terminal repeat (LTR) activity. We found that these PTP inhibitors markedly enhanced HIV-1 LTR activity in 1G5 cells, a stably transfected cell line that harbors an HIV-1 LTR-driven luciferase construct. A direct correlation between the extent of tyrosine phosphorylation and the level of HIV-1 LTR inducibility was seen after treatment with three different pV compounds. Transient transfection experiments were carried out in several T cell lines, and after addition of pV, a marked increase in HIV-1 LTR activity was measured. Monocytoid cells were tested using U937-derived cell lines and were also found to be sensitive to the pV-mediated potentiating effect on HIV-1 LTR activity. A significant reduction of the pV-mediated increase in HIV-1 LTR activity was seen in cells transiently transfected with an HIV-1 LTR-driven luciferase construct bearing a mutation in both NF-kappaB binding sites although detectable levels of induction remained. Electrophoretic mobility shift assays allowed the identification of the nuclear translocation of the NF-kappaB p50.p65 heterodimer complex induced by pV compounds. A dominant negative version of the repressor IkappaBalpha mutated on serines 32 and 36 impeded pV-induced NF-kappaB-dependent luciferase activity. Western blot analysis showed a clear diminution in the protein level of IkappaBalpha starting 30 min after pV treatment of Jurkat E6.1 cells which is indicative of its degradation. On the other hand, no increase in tyrosine phosphorylation was observed on IkappaBalpha itself. Finally, we tested the PTP inhibitors on four cell lines latently infected with HIV-1 and showed a consistent pV-mediated increase in virion production. Thus, our studies suggest that pV-mediated activation of HIV-1 LTR activity is controlled by the nuclear translocation of the NF-kappaB transcription factor, which is mediated by IkappaBalpha serine phosphorylation and degradation, but also by a still undefined NF-kappaB-independent pathway.

Impact of measurement and feedback on vaccination coverage in public clinics, 1988-1994

OBJECTIVE

To investigate whether a reported rise in vaccination coverage in Georgia public clinics during the period 1988 through 1994 was artifactual or real and, if real, to determine the extent to which the rise could be associated with a program of measurement and feedback.

DESIGN

Examination of data from Georgia public clinics, doses-administered records, and National Health Interview Surveys.

SETTING/PARTICIPANTS

Children attending Georgia public clinics.

INTERVENTION

Measurement of vaccination coverage and feedback to providers.

MAIN OUTCOME MEASURE

Vaccination coverage rates.

RESULTS

For the period 1988 through 1994, 136 004 Georgia public clinic vaccination records for children 21 to 23 months of age were reviewed. Median series-completion rates at public clinics rose from 53% to 89%, while indexes of under-vaccination fell: missed opportunities for simultaneous vaccination (6% to 0%), lost contact for more than 12 months (14% to 1%), and first vaccination more than 1 month late (19% to 8%). According to the independent doses-administered database, the proportion of children starting the primary series very late (> or =12 months old) fell from 14% to 6%, and the series-completion index rose from 64% to 83%, suggesting that improvements could not be wholly ascribed to better clinic record keeping. In 1988, vaccination coverage of children 24 months of age in the National Health Interview Survey (NHIS) was 53%, identical to median public clinic coverage in Georgia; in 1993, NHIS coverage was 60%, while median public clinic coverage in Georgia was 90%, suggesting that the rise in coverage in Georgia public clinics exceeded national trends. Patterns within the coverage changes suggest an association with the process of measurement and feedback.

CONCLUSIONS

A marked increase in vaccination coverage occurred in Georgia public clinics associated with a program of annual measurement and feedback.

Drug sensitivity of human immunodeficiency virus type 1 isolates after ribavirin therapy

The antiviral agent ribavirin is effective against several virally induced diseases, and there is evidence that it might prove useful against human immunodeficiency virus type 1 (HIV-1) infection. Thus, there is interest in studying the resistance level of HIV-1 isolates to ribavirin following drug therapy. Low-passage clinical strains of HIV-1 were isolated from 3 patients undergoing treatment with ribavirin for 5-9 months. No significant changes in drug sensitivity were seen for sequential virus samples obtained before, during, and after antiviral therapy. These observations suggest that the appearance of a resistant phenotype is not induced by treatment with ribavirin in HIV-1-infected persons.

Activation of human immunodeficiency virus type 1 in monocytoid cells by the protozoan parasite Leishmania donovani

In this study, we demonstrated that the protozoan parasite Leishmania donovani and one of its major surface molecules, the lipophosphoglycan (LPG), can induce human immunodeficiency virus type 1 (HIV-1) expression in U1 and OM-10.1, two cell lines of monocytoid origin latently infected with HIV-1. Treatment of U1 cells with various concentrations of LPG (1, 5, and 10 microM) resulted in a dose-dependent secretion of tumor necrosis factor alpha (TNF-alpha). Suppression of LPG-induced HIV-1 expression by polyclonal anti-TNF-alpha antibodies further confirmed the involvement of this cytokine. Results from these studies indicate that the protozoan parasite L. donovani can induce the secretion of TNF-alpha that will function in an autocrine or paracrine manner to upregulate HIV-1 expression. Our data suggest for the first time that this protozoan parasite can be viewed as a potential cofactor in the pathogenesis of AIDS.

Have structural adjustments led to health sector reform in Africa?

This paper explores the issue of whether and how structural adjustment in Sub-Saharan Africa has altered the level and nature of state involvement in the health care system. Stabilization and structural adjustment generally entail a reduction in aggregate demand, especially government spending, and a reduced role for the state in the provision of many goods and services. Consequently, there is an a priori concern that stabilization and adjustment in Africa may have resulted in lower health expenditures with deleterious effects on the health status of the population, particularly the poor. This paper concludes that structural adjustment programs in Africa did not reduce public health expenditures. In fact, many countries experienced higher real expenditures after adjustment. The fact that many indicators of health status deteriorated during the 1980s, however, presents somewhat of a paradox given the patterns of health expenditures. This paradox is resolved, by an investigation of the intrasectoral allocation of health expenditures which reveals that there are systematic biases in public expenditures towards tertiary and curative care, and a general weakness in the public sector's capacity to deliver adequate health care services even with higher real health sector budgets. In many countries, these biases have persisted despite government and donor intentions to promote health care reform. Finally, the paper reviews a set of policy and institutional issues which hinder the efficient use of budget resources, including overcentralization of health care administration, inappropriate drug and supply procurement practices, the lack of mechanisms for cost recovery, and poor organization, financial and personnel management. At each level of analysis, the paper catalogs those instances where progress is being made towards effective health care reform, including intrasectoral budget rationalization, administrative decentralization, the adoption of user fees for cost recovery, privatization in service delivery, particularly through non-governmental organizations, and organizational and management reform.

Implementation of a province-wide computerized network in Quebec: the FAMUS Project

General practitioners have busy schedules and are accustomed to working autonomously. But they will take an interest in research issues that could increase their efficiency or improve patient care. The use of medical informatics tools to facilitate collaborative research networks requires that participants accept the tools. This article describes the implementation of a province-wide computing network and discusses the opportunities afforded by the creation of a large central database documenting the process of care.

Homologous interference resulting from the presence of defective particles of human immunodeficiency virus type 1

Defective particles are naturally occurring virus mutants that lack one or more genes required for viral replication. Such viruses may affect positively or negatively the symptoms of the disease. Thus, it is of great interest to measure the role played by defective particles in the process of human immunodeficiency virus (HIV) infection since accumulating evidence indicates that a great proportion of HIV genomes are defective. We used defective particles produced by two stable cellular clones (UHC-8 and UHC-18) to investigate whether they can affect replication of infectious viral particles generated by a human T-cell line transfected with a molecular HIV-1 clone. Progeny virus harvested from UHC-8 cells has no reverse transcriptase and integrase proteins, while UHC-18 has no reverse transcriptase protein. We demonstrate here that coinoculation of a T-lymphoid cell line and of peripheral blood mononuclear cells with defective and infectious particles leads to a dramatic inhibition of virus replication. Defective particles do not interfere with virus production from proviral DNA. Rather, the inhibition of reinfection events seems to be their mechanism of action. This model closely parallels the in vivo conditions and demonstrates that defective particles may limit the spread of infection and progression of the disease by reducing the yield of infectious virus.

The TEAM evaluation approach to Project FAMUS, a pan-Canadian risk register for primary care

The application of the TEAM--Total Evaluation and Acceptance Methodology--to the development of Project FAMUS--Family Medicine, University of Sherbrooke--is described. Project FAMUS is concerned with the establishment of a pan-Canadian risk register, the data being provided from a network of 800 family physicians distributed across Canada. Emphasis is on the first phase of the project and the overall evaluation strategy.

Deconvolution of two-dimensional images with zeros in the transfer function

Although it is generally believed that the information at the zeros of the transfer function is lost and cannot be recovered, this is not true: the information can be recovered, even in the presence of noise, because the lost information is coded into intermediate points where the transfer function is not zero. We extend our previous one-dimensional treatment [Can. J. Phys. 49: 1865 (1971)] to two dimensions and apply the results to the restoration of images degraded by noise and by linear filtering, such as movement blurring. The filter used is an honest filter in the sense that in the absence of noise, it yields a perfect restoration, including frequencies at the zeros of the transfer function. It is shown that the method considerably improves the restoration of linearly degraded real images.

Brain growth and differentiation in two fetal bats: qualitative and quantitative aspects

The development of the main brain components in two fetal bats (one insectivorous and one frugivorous type) is studied quantitatively and comparatively. The telencephalon, cerebellum, and diencephalon grow faster in the frugivorous bat. The brainstem maintains a greater relative volume throughout in the insectivorous type. The morphology and density of neurons in the cerebellum, caudate nucleus, olfactory mitral stratum, and neocortical layer II suggest that there exists an initial delay in development in the frugivorous bat; through subsequent reordering, however, it becomes more advanced in development, in accordance with the more progressive status of the adult forms in its category. In this there may be a certain ontogenetic recapitulation of a possible chiropteran phylogeny. These comparisons also point to the precociousness of the functional determination of those structures that are related to future behavior in a purely deterministic, non-teleological sense. The qualitative differentiation appears to be more significant than might be expected in comparison with the quantitative proliferation. Technical problems involved in the study of brain morphogenesis are discussed, especially the difficulty of distinguishing the respective effects of cell multiplication, cell death, and artificial increase in cell density through tissue shrinkage.

The humoral immune response to type 1 oral poliovirus vaccine in children previously immunized with enhanced potency inactivated poliovirus vaccine or live oral poliovirus vaccine

Sixty-one children who had previously received three doses of enhanced potency inactivated poliovirus vaccine (epIPV) at 2, 4, and 18 months of age and 56 children who had previously received oral poliovirus vaccine (OPV) according to the same schedule were challenged with a single dose of monovalent, type 1 oral poliovirus vaccine (OPV1) between 19 and 52 months of age. Before the OPV1 challenge, the previously epIPV-immunized recipients had a geometric mean poliovirus type 1 microneutralization antibody titer (geometric mean titer [GMT]) of 11.1 IU, which was significantly higher than the prechallenge GMT of 2.2 IU among the children who had previously received OPV. Three weeks after the OPV1 challenge, the GMTs for the epIPV-immunized recipients and the OPV-immunized recipients were 35.3 IU and 5.1 IU, respectively. For the epIPV-immunized recipients, both the prechallenge GMT and the postchallenge GMT were dependent on the D antigen content of the vaccine that they had previously received. A fourfold or greater rise in poliovirus type 1 antibody occurred after the OPV1 challenge in 50.9% of the epIPV-immunized children and in 28.6% of the OPV-immunized children; this difference was statistically significant. For both groups, antibody boosts were inversely correlated with the pre-challenge serum antibody titer. However, the epIPV-immunized children consistently were more likely to boost than the OPV-immunized children at equivalent levels of prechallenge antibody. This experience indicated that OPV1 administration effectively raises the level of serum antibody in children previously immunized with three doses of epIPV, especially in children with lower levels of preexisting antibody. This booster response was superior to the booster response of children who received three doses of OPV.

Serologic response to oral polio vaccine and enhanced-potency inactivated polio vaccines

In a randomized, controlled trial carried out from November 1980 to July 1983 involving 1,114 infants in Baltimore City and in Baltimore and Prince George's counties, Maryland, the serologic response to three doses of two enhanced-potency inactivated polio vaccines was compared with the response to three doses of oral polio vaccine. The mean ages at vaccination were 2.2, 4.7, and 19.9 months, respectively, for the three doses. Seroconversion after the first dose varied from 35% to 84%, and it was higher after oral polio vaccine than after either of the enhanced-potency inactivated polio vaccines for polioviruses types 2 and 3. Approximately two and one-half and 16 months after the second dose, almost all inactivated polio vaccine recipients had antibodies against all three virus types (98-100%). Fewer oral polio vaccine recipients had detectable antibodies to type 1 (89-92%) and to type 3 (96%). After three doses of vaccine, all children had antibodies against types 2 and 3. Approximately 1% of the inactivated polio vaccine recipients and 3% of the oral polio vaccine recipients lacked antibody to type 1. One or two doses of oral polio vaccine stimulated higher reciprocal geometric mean antibody titers against type 2 poliovirus than did the inactivated polio vaccine. For the other two types, the results were mixed. The third dose of inactivated polio vaccine produced significant increases in the reciprocal geometric mean titers against each of the three poliovirus types and resulted in significantly higher reciprocal geometric mean titers after three doses of vaccine for recipients of inactivated polio vaccine than for recipients of oral polio vaccine.

Plasmid stability in immobilized and free recombinant Escherichia coli JM105(pKK223-200): importance of oxygen diffusion, growth rate, and plasmid copy number

Stability of the plasmid pKK223-200 in Escherichia coli JM105 was studied for both free and immobilized cells during continuous culture. The relationship between plasmid copy number, xylanase activity, which was coded for by the plasmid, and growth rate and culture conditions involved complex interactions which determined the plasmid stability. Generally, the plasmid stability was enhanced in cultured immobilized cells compared with free-cell cultures. This stability was associated with modified plasmid copy number, depending on the media used. Hypotheses are presented concerning the different plasmid instability kinetics observed in free-cell cultures which involve the antagonistic effects of plasmid copy number and plasmid presence on the plasmid-bearing/plasmid-free cell growth rate ratio. Both diffusional limitation in carrageenan gel beads, which is described in Theoretical Analysis of Immobilized-Cell Growth, and compartmentalized growth of immobilized cells are proposed to explain plasmid stability in immobilized cells.

Long-term clinical and functional results of sleeve lobectomy for primary lung cancer

Sleeve lobectomy is a lung-saving operation in which a portion of main bronchus is removed in continuity with the involved lobe to preserve distal parenchyma. Current controversies relate to indication and safety of the procedure, adequacy as a cancer operation, and contribution of the reimplanted lobe to overall remaining lung function. Between 1975 and 1985, sleeve lobectomy was done electively in 72 patients with lung cancer. There were no operative deaths, but major complications occurred in 10% of patients. Most resected carcinomas were squamous (65/72). Complete resection was performed in all but five patients. A minimum of 1 year's follow-up information was available for all patients. For patients with N0 disease (n = 34) the cumulative 5 year survival rate was 67%, and for patients with N1 status (n = 34) it was 60%. Although postoperative pulmonary function studies at 5 years (n = 19) show subnormal values, they were not severely altered with regard to percent of predicted (forced vital capacity, 85.9% +/- 17.5%; forced expiratory volume in 1 second, 74.9% +/- 19.4%). Regional function was determined by ventilation/perfusion isotope scanning methods. For 15 patients with right lung bronchoplasties, perfusion ratios were 41.1% right lung/58.9% left lung. For four patients with left sleeve operations, these ratios were 29.3% left lung/51.7% right lung. Washout curves show comparable ventilation between the reimplanted lobe and the contralateral lung. The data show that sleeve lobectomy is a safe and adequate operation for patients with resectable lung cancer. The reimplanted lobe or lobes contribute significantly to the overall remaining lung function.

Prevalence of rubella antibodies in Massachusetts schoolchildren

In 1982, 1,871 (79%) of 2,368 eligible 6th, 10th and 12th grade students in Massachusetts participated in a statewide serosurvey for rubella antibodies. Sera were screened at the Centers for Disease Control (CDC) by a reference hemagglutination inhibition assay at 1:8, equivalent to approximately 15 International Units (IU)/ml. Sera negative by the CDC hemagglutination inhibition assay were retested using an enzyme immunoassay, a passive hemagglutination assay, and a commercial hemagglutination inhibition test. The approximate screening levels were 10 IU/ml, 7.5 IU/ml, and 5 IU/ml, respectively. Overall seroprevalence levels varied from 76.4% screening at 15 IU to 93.1% including seropositives from any of the tests. Persons with a school record of vaccination had significantly higher seroprevalence levels than persons without records. However, only 78.3% of persons with a record had antibody greater than or equal to 15 IU compared with 60.0% without records; considering any detectable antibody, the comparison is 95.6% versus 71.4%. The low titers in vaccinees appeared to be due to a falloff of antibody with time since vaccination. Of students with a single vaccination noted in the record with exact dates, 92.3% who were vaccinated 0-4 years prior to the study had antibody at 15 IU compared with less than 78% of students with antibody who were vaccinated five or more years prior to the study. In contrast, using more sensitive assays, there was no significant decline in seroprevalence with time since vaccination. Revaccination studies and epidemiologic data suggest that almost all persons with detectable antibody whether above or below 15 IU/ml are immune to rubella. Thus, immunity levels in Massachusetts schoolchildren in the 6th, 10th, and 12th grades are probably in excess of 90%.

Self-organizing potential and morphogenetic potential (comparing current embryological and Atlan's views)

The concept of self-organizing potential proposed by Atlan, conceived within the framework of information theory, attempts to explain the emergence of the structures and functions of the organism, as well as the concept of morphogenetic potential, conceived in the embryological laboratories. Are the two theses diverging or converging and/or complementary to each other? The paper indicates, first, the context of Atlan's thesis and the meaning of his concepts of self-organization and self-organizing potential in evolutionary systems as well as in individual systems. It then develops an in-depth analysis of these individual systems and attempts to discern, in Atlan's thesis, the respective roles of the genetic factors (first at the initial stage of the system and then in the course of its development) and of the epigenetic factors in the formation of the individual, particularly during morphogenesis. This analysis reveals some difficulties inherent in the theory and induces the author to propose a few additional distinctions. Finally, the paper underlines the analogies and divergences between the concepts of self-organizing potential and morphogenetic potential.

Molecular cloning of a Bacillus subtilis xylanase gene in Escherichia coli

A gene coding for xylanase synthesis in Bacillus subtilis was isolated by direct shotgun cloning using Escherichia coli as a host. Following partial digestion of B. subtilis chromosomal DNA with PstI or EcoRI restriction enzymes, fragments ranging from 3 to 7 kb were introduced into the PstI or EcoRI sites of pBR325. Transformed colonies having lost either the ampicillin or chloramphenicol resistance markers were screened directly on 1% xylan plates. Out of 8000 transformants, ten xylanase-positive clones were identified by the clearing zone around lysozyme-treated colonies. Further characterization of one of the clones showed that the xylanase gene was present in a 3.9-kb insert within the PstI site of the plasmid pBR325. Retransformation of E. coli strain with the xylanase-positive hybrid plasmid pRH271 showed 100% transformation to xylanase production. The intracellular xylanase produced by the transformed E. coli was purified by ion exchange and gel permeation chromatography. The electrophoretic mobility of the purified xylanase indicated an Mr of 22 000.

Isolation and Characterization of a Xylanase from Bacillus subtilis

Partial characterization of an extracellular xylanase isolated by chromatography from Bacillus subtilis gave a molecular weight of 32,000 and optimum pH and temperature of 5.0 and 50�C, respectively. K m and V max values, determined with a soluble larchwood xylan, were 0.16% and 7.0 � 10 3 μmol min −1 mg −1 of enzyme respectively. The amino acid composition showed more basic amino acid residues than in a previously characterized xylanase from a white-rot fungus.

Diagnosis and long-term follow-up of major bronchial disruptions due to nonpenetrating trauma

From 1966 through 1978, 13 patients were treated for major bronchial disruptions due to nonpenetrating trauma. In 10 patients the diagnosis was made early, and operation was carried out in all of them. Four of the 6 patients with main bronchus avulsion had primary repair and all 4 patients with lobar rupture underwent lobectomy. One patient had a pneumonectomy. There was 1 operative death. In 3 patients the diagnosis was made more than a month after the injury. A bronchoplastic repair was done in every patient. All 7 patients who had repair of a transected main bronchus were assessed 2 to 14 years after operation (average, 7 1/2 years). Flow-volume curves on air and air-helium were normal, indicating no major airway obstruction; this finding was confirmed by clinical and bronchoscopic examinations. Pulmonary diffusing capacity for carbon monoxide was also normal in all patients. Volume measurements by closed circuit method and by body plethysmography showed restriction in 1 patient but no major air trapping. Perfusion/ventilation scans showed homogeneous distribution of air and blood flow in the lung.

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Following the Task Force on the Periodic Health Examination, the authors review the chief preventable pathology and outline norms for the nature and frequency of preventive procedures. They propose a systematic program of prevention and screening of the adult. In order to accomplish this, the initial evaluation of the patient must include the search for risk factors and these are included in the problem list. Finally, tables provide simple and efficient modes of applying this program, which also constitutes a useful research tool.